In a vapor-compression refrigerant cycle device described in JP-B1-3322263 (corresponding to U.S. Pat. No. 6,477,857 and U.S. Pat. No. 6,574,987), as shown in FIG. 7, an ejector 14 is used as a refrigerant decompressing unit and a refrigerant circulating unit. Further, a first evaporator 61 is located between a refrigerant outlet side of the ejector 14 and a gas-liquid separator 63, and a second evaporator 62 is located between a liquid refrigerant outlet side of a gas-liquid separator 63 and a refrigerant suction port 14c of the ejector 14.
In this refrigerant cycle device, refrigerant discharged from a compressor 12 is cooled in a refrigerant radiator 13 to heat water to be supplied. The refrigerant from the refrigerant radiator 13 is decompressed in a nozzle portion 14a of the ejector 14. In contrast, gas refrigerant discharged from the second evaporator 62 is drawn using a pressure reduction caused by a high-speed refrigerant stream jetted from the nozzle portion 14a. The refrigerant drawn from the refrigerant suction port 14c and the refrigerant jetted from the nozzle portion 14a are mixed in a diffuser 14b, and the pressure of refrigerant is increased by converting the speed energy of the refrigerant to the pressure energy of the refrigerant.
In this refrigerant cycle device, only gas refrigerant is drawn into the compressor 12 from the gas-liquid separator 63, and only liquid refrigerant is introduced into the second evaporator 62. Therefore, the gas-liquid separator 63 is required. Furthermore, by using the single ejector 14, a refrigerant circulation into both the first and second evaporators 61, 62 is performed while a refrigerant circulation of the ejector 14 is performed. Therefore, it is difficult to suitably adjust the flow amount of refrigerant into each of the first and second evaporators 61, 62. Accordingly, cooling performance of the refrigerant cycle device cannot be effectively improved.
Furthermore, if the refrigerant cycle device is simply arranged in a vehicle, a mounting performance of the refrigerant cycle device may be deteriorated, and cooling performance of the refrigerant cycle device may be deteriorated.